Abstract: This structural member design method is a method for designing a structural member obtained by forming a tailored blank. The method includes: a weld setting step of performing crash analysis by numerical simulation on an analytical model of the structural member, and setting the position of the weld such that a fracture index of a first region is equal to or more than a specified value and the fracture indices of all remaining regions other than the first region are less than the specified value; and a removal region setting step of setting, after the weld setting step, a region including a portion corresponding to the first region in the joined end portion as a removal region where the exposed portion is formed.

Abstract: A method of designing the width of the weld bead in a tailored blank includes: a model acquisition step for acquiring analysis model data containing elements for the first sheet, elements for the second sheet, and elements for the weld bead; a press-forming analysis step for performing press-forming analysis using the analysis model data to calculate deformation of the various elements when the tailored blank is press formed; and a bead-width designing step for deciding on a design value of the width of the weld bead for each of positions along the longitudinal direction of the weld bead in the tailored blank prior to press forming based on a press-forming-induced change in the width relating to the elements for the weld bead obtained through calculation, to generate bead-width design data indicating the relationship between a position along the longitudinal direction of the weld bead and the design value of the width of the weld bead.

Abstract: A method of manufacturing a press-formed product includes a heating step, a transportation step, and a pressing step. At the heating step, workpieces are heated while a first workpiece W1 is placed on a first group of struts 3 extending upward from a tray body 2, and a second workpiece W2 is placed on a second group of struts 3 to be located above the first workpiece W1 and overlap it. At the transportation step, the second workpiece W2, while located above the first workpiece W1 and overlapping it, is transported, together with the tray body 2, from the heating device 14 to the lifting location. At the lifting location, the second workpiece W2 is lifted upward by the transportation device 46 and the first workpiece W1 is lifted by the transportation device 46 before they are transported to their respective pressing locations.

Abstract: A method of manufacturing a press-formed product includes: a heating step; a transportation step; and a pressing step. The transportation step includes: using claws of a pair of first arms to support the lower surface, at both ends, of a first heated workpiece and lift the workpiece; using claws of a pair of second arms to support the lower surface, at both ends, of a second heated workpiece and lift the workpiece; transporting the first heated workpiece with the lower surface supported, at both ends, by the claws of the pair of first arms and the second heated workpiece with the lower surface supported, at both ends, by the claws of the pair of second arms, where the first and second heated workpieces overlap each other in the direction normal to the sheet surfaces; driving the pair of first arms to lower the first heated workpiece to a pressing location on a press machine; and driving the pair of second arms to lower the second heated workpiece to a pressing location on the press machine.

Abstract: A method of manufacturing a press-formed product includes a heating step, a transportation step, and a pressing step. At the heating step, a sheet-shaped heat storage member 5 and a sheet-shaped workpiece W1 placed above the heat storage member 5 are heated by a heating device 14 while overlapping in the direction normal to the sheet surfaces of the workpiece W1. At a first transportation sub-step, the heat storage member 5 and the workpiece W1 placed above the heat storage member 5 are transported from the heating device 14 to a lifting location while overlapping in the direction normal to the sheet surfaces of the workpiece W1. At a second transportation sub-step, the workpiece W1 placed above the heat storage member 5, when at the lifting location, is lifted upward by a transportation device 46 and transported to a pressing location on a press machine 20. At the pressing step, the workpiece W1 is processed by the press machine 20.

Abstract: This steel sheet has a base steel sheet, a coated portion, and an exposed portion, the shape of the end edge side of the steel sheet and the end portion on the outer side of the base steel sheet is a protruded curve represented by a curvature radius R1 and R1 is 5 ?m or more.

Abstract: This steel sheet includes a first coated portion in which an intermetallic compound layer and an aluminum coating layer are provided on a surface of a base steel sheet in order from the base steel sheet side, a first exposed portion in which the base steel sheet is exposed, and a second coated portion in which the intermetallic compound layer and the aluminum coating layer are provided on the surface of the base steel sheet in order from the base steel sheet side, in which in a first direction which is perpendicular to a thickness direction of the steel sheet and is directed from the first coated portion to one end edge of the steel sheet, the first coated portion, the first exposed portion, the second coated portion, and the end edge of the steel sheet are disposed in this order on one surface of the base steel sheet, at least the first coated portion, the first exposed portion, and the end edge of the steel sheet are disposed in this order on the other surface of the base steel sheet in the first direction,

Abstract: A welding method for obtaining a lap fillet welded joint excellent in tensile strength, without causing an increase in welding deformation, not fracturing at the weld metal when a tensile load is applied, that is, a method of overlaying at least scheduled welding locations of a first steel sheet with a tensile strength of 780 MPa or more and a second steel sheet and fillet welding an end part of the first steel sheet and a surface of the second steel sheet, characterized by providing a reinforcing part at a surface of the first steel sheet at the opposite side to the surface to be overlaid with the second steel sheet and fillet welding one end part of the reinforcing material and the surface of the first steel sheet and by fillet welding the end part of the reinforcing part, the end part of the first steel sheet, and the surface of the second steel sheet so as to be covered by the weld metal.

Abstract: A fillet arc welded joint formed by fillet arc welding at least two metal members, comprising a remelted and solidified portion obtained by irradiating a laser at a weld toe portion of the fillet arc welding of at least one metal member and a region including a boundary of the heat affected zone caused by the fillet arc welding at the surface of that metal member, the remelted and solidified portion being a range from a surface of the metal member to a depth of ½ or less of the thickness of that metal member, an average effective crystal grain diameter of prior austenite at a heat affected zone from a boundary of the remelted and solidified portion at the surface of the metal member to a depth of 0.1 mm in the thickness direction of the metal member being 20 ?m or less.

Abstract: This steel sheet includes a first coated portion in which an intermetallic compound layer and an aluminum coating layer are provided on a surface of a base steel sheet in order from the base steel sheet, the first exposed portion in which the base steel sheet is exposed, and a second coated portion in which the intermetallic compound layer and the aluminum coating layer are provided on the surface of the base steel sheet in order from the base steel sheet, in which in a first direction which is perpendicular to a thickness direction of the steel sheet and is directed from the first coated portion to one end edge of the steel sheet, the first coated portion, the first exposed portion, the second coated portion, and the end edge of the steel sheet are disposed in this order on at least one surface of the base steel sheet, and wherein at least the first coated portion, the first exposed portion, and the end edge of the steel sheet are disposed in this order on the other surface of the base steel sheet in the fir

Abstract: A control arm includes a pair of mounting portions provided separately from each other and a main body portion extending in a X-direction and connecting the pair of mounting portions. At a cross-section perpendicular to the X-direction at a position along the X-direction, the main body portion includes: a first V-shaped member having a first apex and opening from the first apex in a V-shape toward one side in a Y-direction, and a second V-shaped member having a second apex and opening from the second apex in a V-shape toward the other side in the Y-direction. At the cross-section, the first apex and the second apex are joined. At a cross-section perpendicular to the X-direction at the center position of the main body portion in the X-direction, an opening angle of the first V-shaped member and an opening angle of the second V-shaped member are each no more than 150°.

Abstract: A method of production of a welded structure by butt welding two steel sheets (51, 52) by laser welding (11) while supplying assist gas (12) to a back surface of a melt pool (13), whereby it is possible to prevent formation of a through hole in the melt part (53), characterized in that a thickness of at least one steel sheet (52) of the two steel sheets (51, 52) is 0.6 mm or less, the assist gas (12) is a mixed gas (12) containing 10 to 50 vol % of O2 gas, and, when an O2 concentration in the mixed gas (12) is C (vol %), a flow rate L of mixed gas (12) (liter/min) satisfies 30 (liter/min)?C(vol %)×1 (liter/min/vol %)?L (liter/min)<40 (liter/min).

Abstract: A control arm includes a pair of mounting portions provided separately from each other and a main body portion extending in a X-direction and connecting the pair of mounting portions. At a cross-section perpendicular to the X-direction at a position along the X-direction, the main body portion includes: a first V-shaped member having a first apex and opening from the first apex in a V-shape toward one side in a Y-direction, and a second V-shaped member having a second apex and opening from the second apex in a V-shape toward the other side in the Y-direction. At the cross-section, the first apex and the second apex are joined. At a cross-section perpendicular to the X-direction at the center position of the main body portion in the X-direction, an opening angle of the first V-shaped member and an opening angle of the second V-shaped member are each no more than 150°.

Abstract: A welding method for obtaining a lap fillet welded joint excellent in tensile strength, without causing an increase in welding deformation, not fracturing at the weld metal when a tensile load is applied, that is, a method of overlaying at least scheduled welding locations of a first steel sheet with a tensile strength of 780 MPa or more and a second steel sheet and fillet welding an end part of the first steel sheet and a surface of the second steel sheet, characterized by providing a reinforcing part at a surface of the first steel sheet at the opposite side to the surface to be overlaid with the second steel sheet and fillet welding one end part of the reinforcing material and the surface of the first steel sheet and by fillet welding the end part of the reinforcing part, the end part of the first steel sheet, and the surface of the second steel sheet so as to be covered by the weld metal.

Abstract: A fillet arc welded joint formed by fillet arc welding at least two metal members, comprising a remelted and solidified portion obtained by irradiating a laser at a weld toe portion of the fillet arc welding of at least one metal member and a region including a boundary of the heat affected zone caused by the fillet arc welding at the surface of that metal member, the remelted and solidified portion being a range from a surface of the metal member to a depth of ½ or less of the thickness of that metal member, an average effective crystal grain diameter of prior austenite at a heat affected zone from a boundary of the remelted and solidified portion at the surface of the metal member to a depth of 0.1 mm in the thickness direction of the metal member being 20 ?m or less.

Abstract: A method of production of a welded structure by butt welding two steel sheets (51, 52) by laser welding (11) while supplying assist gas (12) to a back surface of a melt pool (13), whereby it is possible to prevent formation of a through hole in the melt part (53), characterized in that a thickness of at least one steel sheet (52) of the two steel sheets (51, 52) is 0.6 mm or less, the assist gas (12) is a mixed gas (12) containing 10 to 50 vol % of O2 gas, and, when an O2 concentration in the mixed gas (12) is C (vol %), a flow rate L of mixed gas (12) (liter/min) satisfies 30 (liter/min)?C(vol %)×1 (liter/min/vol %)?L (liter/min)<40 (liter/min).